Micrometer attachment



May l, 19.51` Y v. H. BURWINKL 2,551,242

MICROMETER ATTACHMENT Filed Sept. 24, 1945 INVENTOR. V//VCE/y 50km/wa@ YPatented May 1, 1951 rrp srATss eATENT .ortica MICROMETER ATTACHMENTVincent H. Burwinkle, Cedar Rapids, Iowa Application September 24, 1945,Serial No. 618,221

The present invention relates generally to measuring instruments and ismore particularly concerned with inside micrometers and attachmentstherefor.

The object and general nature of this invention is the provision of adevice particularly constructed and arranged to receive, in either oftwo optional positions, an ordinary internal micrometer, whereby thedevice may be used as an inside micrometer or as a depth gauge.

This device may also be used as a height gauge, inspection tool, sidedepth micrometer, tool setter, slide parallel, surface gauge, or formeasuring the depth of holes.

These and other objects of my invention will fbe apparent from thefollowing detailed description, taken in conjunction with theaccompanying drawings in which:

Figure 1 is a plan view of a measuring device in Which the principles ofthe present invention have been incorporated.

Figure 2 is a side view of the unit shown in Figure 1 with parts brokenaway in order to show the construction more clearly.

Figure 3 shows an optional mounting of the micrometer.

Figure 4 is a perspective view of an adapter which is provided to permitthe use of this kind or .size of micrometer.

Referring now more particularly to Figures 1 and 2, I provide a base I,consisting of a rectangular block, preferably formed as a steel barground on opposite sides 2 and 3 to a high degree :of accuracy, theopposite sides 2 and 3 being parallel. The bar I is provided with a pairof lopenings 5 and 6, and into the opening 5 is fitted a hollow circularholder 8 having an outer collar .section .9 and a neck section I6, thelatter being .screw threaded internally, as at II. The collar section 3is internally recessed, as at I3 and re- '.ceives a split bushing I4accurately tted therein. The collar section 9 is tapped to receive athreaded set screw I6 which at its inner end bears .against the splitbushing I4. A plug or set-piece 2l is inserted in the threaded portionII of the holder 8 and carries a stud 22, the upper end 23 of which isadjusted accurately to lie in the plane `of the upper face 2 .of theblock I. The end of the latter is tapped as at 2li to receive a setscrew 25 which, when tightened, serves not only to lock the holder 8 inthe block I but also to retain the plug 2l in position therein.

The other opening 5 in the block I is smooth and receives a splitbushing 21, the ends of which are spaced apart .a small distance, as at28 (Fig.

5` claims. (o1. 33 167) 1). The block I is tapped to receive a set screw29 which bears at its inner end against the bushing 21.

An internal micrometer, of conventional construction so far as thepresent invention is concerned, is shown at 30 and for purposes of thisdisclosure comprises a sleeve 3| anda thimble 32. The sleeve carries asocket, as at 34 and an associated clamping member 35 formed to receiveany one of a number of extension rods 36 of different lengths, theselected extension rod being held by tightening set screw 31. Thethimble 32 of the micrometer 33 is provided with a head 39. Themicrometer 30 is so constructed that by turning either the sleeve or thethimble relative to the other end rod 33 will be extended relative tothe head 39 and the amount of extension, or retraction, accuratelydetermined by the measuring graduations 4I.

The micrometer 33 may be mounted either in the holder 8 or in thebushing 21. When mounted in the holder 8, as shown in Fig. 2, the head39 is placed in engagement with the stud 23 and the set screw I6tightened to hold the unit 30 firmly in the holder 8. When mounted inthis fashion, with the selected extension rod 36 in place, the devicemay Abe used for measuring accurately the distance from the face 2 ofthe block I to the part or surface with which the end of the extensionrod 3S is brought into contact. When the micrometer 33 is mounted inthis position the device may, for example, be used in measuring depths.

The micrometer unit 3|l may also be mounted in the opening E, this beingthe position shown in Fig. 3. When the micrometer 33 is in position thesetscrew 29 is tightened which, acting through the split bushing 21,firmly clamps the unit 33 in position but Without marring or damagingthe micrometer. Likewise, when the set screw I3 is tightenedit actsthrough the split bushing I4 to hold the micrometer in position in theholder 8 without marring or damaging the micrometer. When the micrometer33 is inserted in the opening 6, the head 39 is brought accurately intothe plane of the lower face 3 of the block I, and hence the micrometercan then be used to measure accurately the distance from the lower face3, or from the surface on which the face 3 is placed, to the surface orobject with which the upper end of the extension rod 36 is brought intocontact. Thus, the device, arranged in this way may be used as a heightgauge.

This device may be used with different kinds of micrometers and in somecases the micrometerreceiving opening in the base and holder can bereduced by an adapter, shown in Fig. 4. The adapter, indicated byreference number 50, comprises a split bushing I with the ends thereofseparated, as at 52. The bushing 5l has an external diameter such thatit fits snugly within either of the bushings I4 and 21, wherebytightening either of the set screws i6 or 2S will act through both splitbushings to clamp the micrometer in place.

While I have shown and described the preferred form of my invention, itis to be understood that my invention may take various forms, as definedin the appended claims.

What I claim is:

1. A measuring device comprising abase having spaced-apart upper andlower -fac'e's ardliavin'g a pair of apertures therein, ,a micrometerholder mounted in one of said apertures, a plug disposed in said holderand adapted to position thehead of an internal nicrometercarried therebyin the plane of the upper' surface of saidbase, means for clamping saidmicrometer in said holder, and

other means adapted for clamping a micrometer in the other aperturein'sai/dba'se.v

2. A measuring device comprising a base having spaced-apart upper andlower surfaces and having 'a pair of apertures therein, means forclamping a micrometer in one of said apertures *with the end of the headof said micrometer disposed in the plane of the Vsaid lower surface ofthe base, and other meansfor'selectively clamping the Ysaid micrometerin theA other ofv said apertures with the end of the head ofthemicrometer in the plane of the said upper surface of the base, the lastmentioned clamping means including a sleeve, receivable in the other oflsaid apertures, and having' a portion thereof extending beyond the saidupper surface of the base, the said sleeve having an aperture in theupwardly extending portion thereof for receiving the micrometer andhaving stop means therein disposed in the plane of the upper surface forpositioning the head of the micrometer. Y

3. A device for use with an internal micrometer comprising a base memberhaving spaced, parallel, upper and lower surfaces, a sleeve received inan openingY in said base, said sleeve having a portion thereof'eitending above the upperl of said surfacesand said'portin having anaperture therein for thereception of one end of an internalmicrometenthe sleeve having stop means therein positioned in the planeof the upper surface of said' base and adaptedto position the head of amicrometer in the plane of the said upper surface, means securing thesleeve in the opening, and means for securing a micrometer in theapertures in the said sleeve.

4. In a base for a measuring instrument having two parallel faces, anopening leading through the base at right angles to the parallel faces,a hollow, circular holder adapted to be tted into the opening, saidcircular holder having an outer collar section and a neck section, theneck section being screw threaded internally, the collar section beinginternally recessed, and a split bushing accurately fitted within therecess, a threaded set screw adapted to have threaded engagement with atapped opening leading through the collar and thetap'ped opening beingso placed that when the set screw kislocked down, its inner end bearsagainst the split bushing, a set piece inserted in thth'read'ed Vpdrtihof the holder and having a stud whereby the set piece may be adjusted sothat the upper end of the stud is in the plane of the upper faceof theblock, and a set screw for holding the holder and the set piece in placewhen properly adjusted.

5. In a device of the character described, means for mounting an insidemicrometer on a block so that'the inside micrometer may be supportedwith one of its heads having the end thereof in the plane of the uppersurface Vof the block, comprising a hollow, circular holder'having anouter c01- lar section and a neck section, thel neel; section beingscrew threaded internally, the collar section internally recessed andthe block having an opening therein for receiving the neel; section,means for'locking the thimble of the internal micrometer in the collarsection, and plug means adllStable'within the neck sectionfor up anddown movement to permit adjustment thereof. so that the head of themicrometer may have its lower surface in the plane of the upper surfaceof. the' block.

' VINCENT H. BURWINKLE.

REFERENCES CIVTEIY)r The following references are of record in the le ofthis patent.:` UNITEDv STATES PATENTS Number Name Date 374,168 BarnesDec. 6,; 1887 1,226,574 Nielson L `May 15,1917 2,030,864 Gielow Feb. 18,1936 2,417,150 Beiry Mar. 11,' 1947 FOREIGN PATENTS Number Country Date143,615 Great Britain May 25, 1920

